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RESEARCH PRODUCT

Complexes of organometallic compounds. L. The correlation between 119Sn mössbauer isomer shifts and calculated partial charges on tin in adducts of tin(IV) and organotin(IV) halides with phosphorus and oxygen donors

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Abstract The relationship between Mossbauer isomer shifts, δ, and atomic charges on tin, QSn has been studied for homologous series RnSnhal4−n· L2 [ n = 0−3; L2 = donor atoms of 1, 2-bis(dipheylphosphino)ethane, N, N′-ethylenebes(salicylideneimine) and N, N′-ethylenbes(acetylacetoneimine)] and Snhal4· 2PR3. Semiempirical values of QSn have been calculated by two methods based on the concept of orbital electronegativity equalization upon bond formation. Linear correlations δ/QSn are obtained, which can be function of the coordination number of the metal atom, for terms of the series characterized by different orbital electronegativities of atoms directly bound to tin. Deviations occur for adducts AlK2SnXl2· L2 and AlKSnCl3· L2, as well as for Snhal4· 2PR3, on varying the nature of AlK and R radicals respectivity. The inconsistencies are attributed to under- and over-estimate of inductive effects by the two methods of calculation of QSn, respectively, with reference to the related variations of δ's.